clean up
clean up

`Helper.sortPosts` was already mutating the argument, so there was little point to allocating a new object.
Also removed the side-effect of `compileJS` mutating the `postsMetadata` argument -- the posts metadata is now sorted before being returned from the function that generates it (`generatePosts`).

mauricionr/harmonic,viniciusdacal/harmonic,robsongajunior/harmonic,thotty/harmonic,JSRocksHQ/harmonic,joaopauloti/harmonic